Safety device for door-locks.



H. 0. SMITH.

SAFETY DEVICE FOR DOOR LOCKS.

APPLICATION FILED JAN.2. 1917.

1 ,23,5 Patented Oct. 16, 1917.

I 6 I 5 1 /'L/ 411 5 9 M e i E i V I A? V um I' H E 7 v I j i i j/f '1 A l i i I HARRY 0. SMITH, OF ST. PAUL, MINNESOTA.

SAFETY DEVICE FOR DGOR-IiOCKS.

Specification of Letters Patent.

Patented Oct. 16,, 191

Application filed January 2, 1917.. Serial-N0. 140,223,

Total] whom it may concern .1

Be it known. that I, HARRY (3., SMITH, a

citizen of the United States, and resident of -.to. provide a guard for looks or latches,

whereby, the keyhole or way of the same will be closed, consequently, preventing insertion of the master or duplicate keys into the lock, the key hole closing means being soconstructed as to permit locking thereof within the lock or latch key hole, thus, preventing removal of the same by persons other than the possessor of the key for unlockingthe closure means.

As an object of equal importance, the invention aims to provide a key hole guard which is portable in character, thereby, permitting the same to; be carried by a person when not in use, the construction of the,

guard being such as to allow the placing of the same within the key hole of a lock without alteration thereto.

Among other aims and objects of the invention may be recited, the provision of a guard of the character mentioned with a view to compactness, and in which the number of parts are few, the construction simple, the cost of production small, and efliciency and operation high.

All of the foregoing together with additional advantageous details and arrangements of the parts of the preferred embodiment of my invention will be clear from the specific description hereinafter contained, when read in connection with the accompanying drawings forming a part thereof, wherein said embodiment of the invention is illustrated for the purpose of facilitating a full understanding of the present improvements.

In the drawings:

Figure 1 is a longitudinal vertical section of my improved key hole guard as applied to a conventional form of door lock;

Fig. 2 is a front elevation of the same; and

Fig. 3 is a top; plan in detail of the key pin receiving way filler plug.

Similar characters of reference are: employed inv all of the above described views to indicate corresponding parts.

Referring now more specifically to the drawings, itwill be noted, that I have shown by way of illustration, my improved key hole guard as applied to a conventional type of door lock, indicated by the numeral 1, which lockis provided, with the ordinary key hole 2 whereby a key may be inserted therein to permit actuation of the lock or bolt, The improved key hole guard comprises a substantially rectangular filler block 3, the said block being of a size and shape complemental to the bite receiving way of the key hole and also being adapted to be received thereby. To prevent twisting of the inner. extremity of the filler block 3 within the key hole 2, a reduced extension l is formed upon the inner extremity thereof and is adapted to be engaged with a portion of the lock 1. A plurality of, vertically disposed bores, general-1y indicated by the nu-. meral 5 are arranged longitudinally of the filler block 3 and receive therein eXpansible coiled springs 6', which springs serve tolyieldably seat a plurality of tumblers 7 Upon the upper portion of the filler block 3, I form a tapered cylindrical housing 8, while within the same, approximately intermediate the ends thereof, a, fixed lug 9 is; arranged the purpose of which will be hereinafter apparent. It will be noted, that the tapered cylindrical housing 8 is adapted to, be received within the pin receiving way of the key hole 2, the outer portion or extremity thereof, by reason of its greater di ameter being snugly received by the forward portion of the key hole 2.

With a view toward providing means whereby the filler block 3 will be. maintained in proper position within the bite receiving way of the key hole 2, there is rotatably arranged within the tapered cylindrical housing 8 a tapered cylindrical plug 11 having a spindle 12 formed upon its inner eX tre mity which spindle carries a lug 13,v the lug serving as means for engaging; a fixed or immovable portion of the lock 1, at times, in order that withdrawal of the filler. block 3' and the cylindrical plug 11 will be prevented until the lug 13 is disengaged prevent any material transmission of pull to the lock portion engaging plug 13. A plurality of bores or seats generally indicated by the numeral 15 are arranged longitudinally of the filler plug 11 and are adapted to receive therein the various tumblers 7.

Thus, it will be evident, that when the yieldably seated tumblers 7 are engaged with their respective pockets 15 formed in the plug 11, further rotation of the said plugs will be'prevented and consequently, the lug 18,- which is now in upright position will be securely engaged with the fixed or immovable portion of the lock 1. In addition to serving as means for preventing the transmission of pull and the like to the lug 13, the

plug 9 also serves asmeans for maintaining the plug 11 in such position as will permit the alining of the pockets 15 with the tumblers'Z, at all times. Further, it will be appreciated, that the spindle 12 will not only serve as means for supporting the lug 13 but will also serve as a brake for the inner extremity of the plugll, thereby, preventing the twisting or moving of the same to i one side in effort to loosen it. A longitudinally disposed key way 16 is formed within the plug 11 in alinement with the tumbler pockets 15 of the same. Thus, by inserting a suitable key within the same,the various tumblers 7 may be depressed within their respective bores 5 against the tension of the springs 6 and the plugs thereby released in order that the same may be rotated upon itself to disaline the lugs 13 with the fixed or immovable portion of the lock 1 and consequently, permit withdrawal of the filler block 8 together with the plug 11.

It may be here noted, that the tumblers 7 are formed of different lengths, thereby,

- causing the particular coiled spring upon which the guard is to be placed under varying tension and permitting certain of the same to be more readily depressed than others, these, being preferably arranged adjacent the inner extremities of the filler block 8 to permit ready insertion of the key into thekey way 16 and the depression of the said tumblers. The vertical'slot 17 in the front end of the plug 11 is for the re- Copies of this patent may be obtained for the several-parts butmay be modified within a wide range without departing from the essence of the invention, the construction shown and the description based thereon being intended to be taken in an illustrative rather than a limiting sense.

I claim:

1. A key hole guard for looks, "including a filler-block adapted for insertion within the bite receiving portion of the key hole, a tapered cylindrical casing formed upon the upper portion of said filler block receivable within the pin receiving-portion of the key hole, a cylindrical plug rotatably received within said housing, means projecting from rear end of said plug for engaging the'lock to prevent withdrawal therefrom, said plug having a longitudinal and transversely extending slot in the wall and front end of the same respectively for the reception of a turning key, and a plurality of yieldably seated tumblers arranged within the filler block and adapted to engage the longitudi-- nal slot in the plug to releasably securesaid plug against rotation.

2. A key hole guard for locks, including a filler block adapted for insertion within the bite receiving way of the keyhole, a tapered cylindrical housing formed upon the upper portion of said block, a laterally extending arm arranged upon the lower ex.- tremity of said block and engageable with the lock for bracing the same, a .plug rotatably received within said housing, a laterally extending spindle carried by said plug, a vertically disposed plug on said spindle and adapted for engagement with a portion of the look at times, a plurality of yieldably seated tumblers arranged on the filler block, said filler plug having a longitudinal and transversely extending slot in the Wallvand front end thereof respectively, the plug hav ing spaced enlargements on the slot to .receive the tumblers to releasably secure said plug against rotation, and guide means carried by the filler block and engaged With the filler plug for preventing relative movement I of the same.

In testimony whereof, I affix my signature hereto. 7

HARRY G. SMITH.

five cents each, by addressing the Commissioner of Patents,

Washington, D. G. I Y 

